Boring lathe



R. L. HIBBARD.

BORING LATHE. APPLICATXON FILED AUG.26, 1918.

R. L. -HIBBARD.

BORING LATHE.

APPLICATION FILED AuG.2e, 19111.

6 SHEETS-SHEET 2.

R L. HIBBARD.

somma LATHE. APPLICATION FILED AUG.26, 1918.

e SHEETSLSHEET 3.`

Eatented Aug. 8, 1922.,

R..L. HIBBARD.

BORING LATHE.

APPLICATION FILED AUG.26. 1918.

R. L. HIBBARD.

BORING LATHE. APPLICATION FILED AUG.26, 1918.

Patented Aug. 8, 1922.

E SHEETS-SHEET 5.

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MQA/. 1 l' d. y

.ROBERT L. I-IIBBARD, OF BELLEVUE, PENNSYLVANIA.

BORING LATHE.

Application filed August 26, 1918.

To ZZ w/iom t may concern:

Be it known that Bonnin* L. limi-MRD, a citizen of the United States of America, and a resident of Bellevue, Allegheny County, and State of Pennsylvania, have invented certain new and useful improvements in Boring Lathes, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to boring machines and has special reference to large horizontal machines of the type in which the boring tool is relatively :fixed and the work revolves or vice versa. lt furthermore pertains to boring lathes which are particularly adapted for boring guns or rifles of large calibre and great length, and which are necessarily provided with long boring bars.

@ne object of my invention is to provide a machine of the aforesaid character that shall be constructed and arranged in such manner as to render the usual auxiliary bed or bench unnecessary.

Another object is to minimize the strains on the machine without limiting its swing, by producing a feed screw which acts upon the tailstock relatively close and parallel to the boring bar without extending adjacent to the work.

A further object is to provide a relatively simple lathe structure in which the fixed bar support and its connected members may be readily and quickly adjusted longitudinally of the lathe and fixed to accommodate the length of the work in the machine.

Still another object is to provide an intermediate bar support between the tailstock and the fixed bar support, and means for automatically adjusting its position as the tailstoclr approaches the fixed bar support or is withdrawn therefrom.

rinotlier object is to provide a simple and improved change gear structure to enable the gears to be quickly and easily changed to meet the desired conditions.

Other objects and advantages of my invention will be hereinafter set forth, and i will now describe the same in detail with reference to the accompanying drawings and set forth the novel features thereof in appended claims.

Referring to the drawings:

Figure 1 is a longitudinal elevation of a boring lathe arranged and constructed in Specification of Letters Patent.

Serial No. 251,441.

accordance with my invention and constituting an embodiment thereof.

Figures 2, 3 and L1 are partial elevations corresponding to Figure 1, showing the same machine with its movable parts adjusted to different positions to illustrate the mode of operation.

Figure 5 is an end elevation showing the head stock and change gearing drawn to a larger' scale.

Figures 6 and 7 are sectional elevations showing in detail the respective sets of quick change gears which are shown in elevation in Figure 5.

Figures 8, 9 and 10 are detail views of the adjustable stud arms which form parts of the change gear mechanisms.

Figure 11 is a sectional detail view on the line 11-11 of Figure 6.4

Figure 12 is a plan view showing a detail of the splined stud shaft and adjustable` key of the gear change mechanism.

Figure 13 is a longitudinal sectional elevation of the tailstock and feed screw mechanism.

Figure 14e4 is a plan view of the same parts.

Figures 15, 16, 17 and 18 are transverse sectional elevations taken respectively on the lines 15-15, 16-16, 17-17, and 18--18 of Figure 13.

Figure 19 is a sectional detail View showing the feed screw motor clutch.

Figures 247 and 21 are detail views of the feed screw driving gears.

Figures 22, 23 and 24 are views of modified structures foil effectively adjusting and controlling the position of the intermediate bar support.

Like parts designate c( responding lmits in all the figures.

General description.

The boring lathe illustrated, which constitutes an embodiment of my invention, is particularly adapted for boring guns or rifles of large calibre. In general, it coinprises bed 9, a head stock 10, a face plate 11, a driving motor 12, tool carriages 13, a driving shaft 14, a feed screw 15, change gearing 16, a fixed bar support 17, a spaced support 18, a quick return motor 19 mounted thereon, a tailstock 2O which is slidably mounted on the bed between the spaced supports, a boring bar 21, and a movable, intermediate bar support 22.

affects' the adjustment of the spaced sup-A ports 17 and 18 and their attached parts.

rThe supports 17 and 18 constitute bearings for the feed screw 15 to which they are connected in such manner that they always maintain a fixed relation to each other and follow any longitudinal adjustment of the y feed screw section.

@flange gearing.

v The operative driving connection between the spindle 26 ol the lathe and the ltjlriving shaft 14 will now be discussed in detail, spe.

cial reference being had. to Figures 1, and 5 to 12 inclusive. v

Aiiixed to the head end of.' the driving sha'lt 14 is a gear' wheel 27, a bushing 28 and a 'shear pin 29 being interposed te avoid stripping the gears in case ot accident, and aiiiXed to the spindle 26 is a pinion 230.' A stud 31 extends outwardly iirom the head stock and has a sleeve 82 rotatively mounted thereon and held in positionv by nuts A gear wheel 34 is aliixed to the sleeve at its inner end and meshes with the pinion 50l on the spindle 2G. There are mounted on the sleevea pair of pinions and 36 et different size and either one or the other ot them is active depending on the position oit anadjustable key 37. ed in a spline or' keyway 38 in the sleeve and has at its outer end a lug 39 which engages an annular handleA grip 40. The movement of the key is limited longitudinally of the sleeve and its extreme positions are accentuated by a ball 41 which is pressed by a spring'43 into engagement with depressions 42 in the sleeve. rlrhe sleeve, the key,

and the handle are shown on a. larger sealein Figures 11 and 12.

Pivotally mounted on the inner end oit the stud 81 is a radius arm 45 which has a perforated lug or sleeve 46 at its outer en'd in which a movable stud 47 is mounted. The innerend of the stud 47 is screw-threaded as shown. at 48 and engages a. nut 49 which lits into a curved, channel-shaped slot 50 in a fixed bracket 50a. rllhe curvature of the slot is centered about the axis ot the stud 31 so that when the stud 47 is loosened in the nut 49 both parts are free to swing with the arm 45 about the stud 81 as an axis. rFhe stud 47 extends outwardly beyond the arm 45 and supports a sleeve 51 This ke is slidabl mount- Y Y s to which a gear wheel 52 is attached and meshes with the pinion 35, the pinion 53 meshing with the gear wheel 27.

rlhe outer end or theystud 47 is square or is otherwise formed at 54 to receive a wrench, nuts 58 being utilized to hold the sleeve 51 in place.

lThe arrangement of parts is such that the stud 47 can be turned very easilyto either tix the stud in position, or to release it so that the arm 45 may be swung and the stud djusted to` another position.

Furthermore, thenuts 55 can easily be removed and the gear 53 removed and replaced by a gear of a 'different size. rllhe gear 52 will continue in mesh with the pinion y 47 and is interposed between the pinion 3G" and the gear wheel 27. The adjustable stud 5'( is mounted in a radius arm 58 winch swings about the center oit the ieed screw section 14 as an axis so that the pinion 2:56 may be removed and replaced when it is desired to changethe gear ratio.

Assuming that the gear rat-ies are chosen as represented in Figures 6 and 7, a change from relatively low speed suitable for a heavy r'oughing cut,k to high speed suitable for a finishing cut, is effected very quickly and easily by means oi the adjustable key 37. When the handle 40 is pushed inwardly into the position shown in Figure G, the key engages the key slot in the pinion 35, establishing the driving connectionl from the spindle 2G through the gear wheels 80, r34,

and 52, and 27 to the feedscrew section. @n the other hand, if a relatively high speed is desired, the handle 4() .is pulled outwardly to the position shown in VFigure 7 and the key then engages the key slot in the pinion 36. Connection isi thus established troni the spindle 2G through gears 30, 34, 36 and 5G and 27 to the feed screw section.

The* stud 57 cooperates with a sector slot 59 in a lixed bracket 60 and is adapted to receive a wrench at its outer end so that it can be set in any desired position.

Attention is particularly directed to the tact that it is possible to loosen the stud and make the adjustment without reaching behind any of the gear wheels as is necessary in the usual arrangements ot the prior art.

The radius arm 45 is shown in detail in Figure 8. while the radius arm 58 is shown in Figure 9. The formation of the lined bracket 50 and the nut which cooperates with the sector slot 50 therein, isv clearly shown in the sectional detail view of Figure 10.

Fixed bm" support.

The feed screw driving shaft 14 is not necessarily screw-threaded but is gplined and has slidably mounted on it a sleeve 61 to which a pinion 62 is secured. The sleeve has an annular slot 63 which is engaged by a fork G5 on a rack bar 6G. The latter is mounted in bearings 67 in the fixed bar support 1 7. It is adapted to be actuated by a gear segment 63 on a transverse shaft 69, which extends outwardly through a wall of the support 17 and has a crank arm 70 affixed to it. The arm is provided with a handle 71 and an accentuating pin 72 which is spring pressed into engagement with notches in the casing of the support.

The arrangement of parts is such that when the crank handle is turned in one position the pinion 62 meshes with the gear wheel 73 at the head end of the feed screw section 15 and when the crank arm is moved to its opposite position the sleeve 61 and pinion 62 are moved into the position shown in broken lines in Figure 13, the pinion. being then disengaged from the gear 73. rlhe relation between the gears is determined entirely by the adjustment of the crank arm and is independent of the position of the fixed bar support and of the Afeed screw sections 111 and 15 relative to each other, the arrangement of parts being such that when the fixed bar support 17 and its connected parts move longitudinally on the bed the sleeve 61 slides but does not turn on the splined feed screw section 14.

Spacecl support.

The spaced support 18 is formed to provide a bearing 83 for the tail end of the feed screw section 15 and constitutes a support for the quick return motor 19 which is geared to the feed screw section 15 in any suitable manner. As shown in Figures 13, 18 and 19, the gear wheel 74: is aliixed to the fee-1l screw section l5 and meshes with the pinion 75 ou a stud 7G. `vlvlounted on the same stud is a gear wheel 77 and a sliding key 78 is provided for the purpose of either coupling the pinion 75 to the stud 7G or releasing the pinion 75 so that it is free to turn on the stud. The sliding gear is structurally similar to the key 37, already described, and is similarly actuated by an annular handle 79.

A gear 77 is connected by gear wheels 80 and 81 to the shaft 82 of the quick return motor 19. At one end of the bearing 83 is the gear 741- and at the opposite end of the bearing 83 is a gear 84 so that any longitudinal movement of the shaft section pr duces a like movement of the support 13.

The feed screw 15 is similarly connected to the fixed bar support 17 so that while the fixed bar support constitutes a bearing for the screw any longitudinal movement of the screw is necessarily transmitted to the lined bar support. ln other words, the feed screw 15 is rotatively attached to the spaced supports 17 and 18.

Ta/Z stocks.

rllhe tail stock 2O has a relatively long base 35which is slidably mounted on the bed of the lathe and it is provided with a nut, or screw-threaded bushing 35 which is removably afliXed in position by bolts 87. The feed screw 15 is in cooperative engagement with the nut, the arrangement being such that if the feed screw is longitudinally allixed it produces, when rotated, .a longitudinal movement of the tail stock on the lathea The boring bar 21 is atlixed at one end to the tail stock and extends toward the head stock through the intermediate bar support and the lined bar support 17.

Attention is directed to the fact that the feed screw 15 is relatively close to the bor-in bar and is so arranged that while it is above the bed of the lathe it does not in any wa., interfere with the work because it does not extend toward the head stock beyond the fired bar support 17. lt ist ierefore evident that the screw section 15, if desired, may be located even closer to the boring bar than shown in the drawings, with the advanta that since the forces exerted by the feed screw acting upon the nut 36 to move the tail stock in one direction and the reaction of the boring bar tending to oppose such movement constitute a force couples-the strains upon the tail stock and upon the mechanism are very much reduced by keeping the opposing foroes close together'.

Intermediate bam support.

The intermediate bar support 22 may be omitted if the length of the boring bar is not great relative to its size and on the other hand it may be desirable to provide two or more in termediato supports if the bar 'is Yery l have Villustrated a single internieffliate bar support and in this connection l will explain the operation in case more than one is employed.

The support 22 has a sleeve or bearing box S3 through which the boring bar 21 extends and it is provided with a rotatable nut 39 which is threaded onto the feed screw 15 as clearly shown in Figure 13. The nut has a flange 90 at one end and a gear wheel 91 at the other so that it is held against longitudinal movement relative to the support, but is free to turn therein. The gear wheel 91 meshes with the gear wheel 92 which is slidablyv mounted on a spline shaft or spindle The gear 92 has flanges 9-1 so that it moves on the shaft 93 to correspond with the The shatt'98 is mounted in suitable bear-` ings 95 and 9G in the xed bar support 17 and in the spaced support 18, and extends through a bearing 97 in the tail stock. lt is provided with a gear 98 which meshes with the gear 8&1 on the feed screw section 15. The arrangement of parts is such that the shatt 93 is driven at about one-halt' the speed of the feed screw section 15 and consequently "the nut 89 is rotated at about halt speed, thereby causing ther nut to travel at one-halt the speed at which it would travel due to the rotation of the feed Screwfitselt. lic' it is assumed that the intermediate bar support is centrally located between the tail stock and fixed bar support, as shown in Figure 1, the intermediate bar support and the tail stock are timed to come together as shown in Figure 3, and the intermediate support always maintains a central position as indicated in Figure 2.

it more than one intermediate bar support is utilized the speed ot each will be determined according to its position and it will only be necessary to utilize a different gearl connection between the sha'lt 93 and the rotatable nut which is mounted in each interv tated at some speed which is less than that corresponding to the pitch of the feed screw, the bar supportiwill travel ata less speed than the tail stock and the speed at which it moves can readily be determined by gearing.

'lhe arrangement above described has the great advantage of being not only operative as the boring bar is advancing toward the head stock but is automatically operative to return the intermediate bar support to its intermediate position when the boring bar is being retracted.

ln Figure 22 l have shown a modified arrangement for causing the intermediate bar support to advance at the proper speed and in which the necessity for an auxiliary shaft such as the shaft 93 is avoided. In this arrangement a driving gear 100 is sli-dably mounted on the feed screw section 15 which in this case is provided with a spline 101to cooperate with the gear key 102. The gear 100 meshes with the gear 103 which is aiiiXed to a gear axle stud or shaft 104; on they intermediate bar support. The gear 105 is allixed to the same shaft or axle and meshes with the gear 91 which forms a part oit the nut 89.

The teed screw 15 in this case has the dual 'function oit iced screw and driving shaft for rotating the nut 89vat alower speed than the feed screw.

rlhis arrangement is not preferred on account ogt the tact that it necessitates `providing aylreyway or spline in the feed screw but in many cases this will not be objectionable.

Still another modification ot i my invention is shown in Figure 23 in which the nut 89 is replaced by the nut 106 which has flanges 1,07 and is mounted in a tapped hole 108 in the intern ediate bar support 22. lt is externally threadedrto cooperate with the tapped hole and has 'a low pitch threatL reia-` tive to the pitch of the feed screw which is usuailyvery high. Thenut is alsov inter-- nali-y threaded to cooperate with the iced screw and in length it is considerably vgreater than the section ot the support through which it extends. The arrangement oi' parts lis such that when the ieed screw yfirst active in advancing the tail stoel; theA intermediate bar support remains statioir ary and the nut 10G rotates troni tbie'position shown in 'full lines'to that shown in brolrenlines in Figure The pitch oi the ot the itianges now engages the supportand consequently the intermediate bar support advances at the same speed as the tail stock.

This' arrangement'obviously does notl keep f the intermediate bar support central be* tween the tailstocl and the 'fined bar sup port 17, but it prevents thedistance between supports any time troni being greater than that of the retracted tail stock shown in Figure 1. vln the reverse operation the nut will rotate and travel 'from one position to the other relativ-e 'to the intermediate bar support while the taii stock is being retract ed to an intermei'liate position and then the intermediate bar su) port will move back at the same speedfas the tail stock until it reachesrits initiall central position.

Operation Outlined.

The operation ot the complete machine will be readily understood trom the operation ot the'various sections as above dcscribed..v Attention is, however, directed to the tact. that whenv the suitable gear changes have been made tor work of a given type or size the speeds are quickly adjusted for roughing and )finishing cuts without removal and change oi' gears, by shifting the position iis Cfr

by disconnectiigu the driving shale-this being` accomplished by swinging` the crm lr handle 'LZ1 to the desired position-eind coupling the quick return motor 19 to the 'feed screw 15, by means oi" the slip gear handle 79. lllhen the parts are in their initial positions the quiclr return motor 19 is disconnected from the feed screw and the latter is connected with shaft 111 ready for a new cutting operation in which the work and the Lteed are synchronized or cooperatively dependent in speed.

Machines for the same general purpose, hitherto constructed., comprise a bed on which a large and expensive casting called a bench, is mounted, the tail stockY of the lathe being movably mounted on the bench.

ln this typev of construction the bench must be controlled l y a feed screw which extends the entire length oi the machine a second screw is employed tor adjusting the tail stock on the bench.

My improved structure renders 'the bench unnecessary7 avoids the expense and weight of this member, and provides a simple and effective means 'for adyusting` the tail st clr.

Attention is directed to the Ytact that l1 use instead of the halt-nut usually employed to engage the feed screw and avoid the screw supports in machines ot this character-a complet-e nut 86 at the tail stock 20. The screw is supported on one side oit the tail stock by the intermediate bar supports and may be also supported by speed nmvablc screw supports 110 and 111. on the opposite side ot the tail stockj as shown in the niodilication ot Figure 2d to which reference may now be had. A

As here shown there are two intermediate bar sup-ports 11i), and 113 to which the screw supports 110 and 111 are respectively connected. rlhis is accomplished by a bar 11e which is ai'iixed at its ends to the intermediate bar support lli). and thel screw support 1107 and by a tube 115 uf'hirh loosely sarrounds the har 114Y and aiixed at its respective ends to the intermedi supe port 11.3 and the sti .w support 1"fl-,lith this arrangement as the tail stock ward 'from its roar position in oper encounters the `hrst intermediate bar por"` which it carries for Yard n" `h i' lirst rear screw support 111 being; forward at the same 'time by reason of connection above described. ln the same way the intermediate bar support 119. is carried forward and carries with it the second rear-screw support 110.

It is evident that no other means for moving the intermediate bar support is necessary with this arrangement and that one or more intermediate bar supports may be employed with a corresponding number oit connected rear screw supports. @t course, a -ewer number ot screw supports may be found necessary in which came some, but not all oli the intermediate bar supports will be connected to the rear screw supports. @ther arrangements will suggest themselves 'to those skilled in this art.

Structures 01" prete struction have been illustrated and described for the purpose of showing ways in which this invention may be used, but the inventive thought upon which this application is based, is broader Ythan these illustrative embodiments thereofa anditherefore intend no limitations other than those imposed by the appended claims.

That l claim is:

' 1. A boring machine comprising a bed, a fixed bar support adjustable thereon, a spaced support also on the bed7 a feed screw extending between lsaid supports androtav tively but non-slidably attached to each ot them, and a tail stock mounted on the bed between said supports and arranged to constitute a. travelling nut relative to said screw.

2. The combination with the guide ways oit a machine tool, ot an adjustable boringbar unit mounted thereon, said unit com# prising a pair of spaced supports adjustably aliiXed to said guide-ways, a screw shaft maintaining' said supports in spaced rela-y tion, a tail stocl between said supports, and means operatively connecting` the tail stool: and screw shaft whereby rotation ot the latter imparts translational movement to the former.

El. ril'hc combination as in claim 2, and means on one of said supports 'for driving the screw.

et. A boring machine comprising a bed, a lixel bar support adjustable thereon, a spaced support also on the bed, a teed screw extending between said supports and rotatively but non-slidably attached to each ot' them and a tail stock mounted on the bed between said supports and having a tapped hole to cooperate with the feed screw7 means on one oit said supports for driving the screw, and means for temporarily securing the tail stock to the bed to etllect an adjustment of the spaced supports and the toed screw.

5. .A boring lathe comprising a bed7 a head stock, a pair ot spaced supports one of which supports a boring)` bar, Vthe supports being' slidable on said bed screw rotatively but non-slidably attached to said spaced supports, and means for cooperating with the screw and adapted to be fixed Jtor the purpose of adjusting the spaced supports.

6. The combination with the guide ways of a machine tool, of an adjustable boringbar unit mounted thereon, Said unit com- ;'ed form and con-v i head stock, ak pair of spaced supports 'slid prising a screw, a boring-bar-ruiding sup. port at one end of .the screw, means supported by said `guide-ways and operativelyy connected to the screw for driving; the latter,`a tail stockr to which a boring` bar is securable, and means operatively connectingthe tail stock to the screwwhereby rotation able on said bed, a feed screw rotatively 4but noni-slidabjly attached to said spacedsupports, and a tail stock between the spaced supportsv cooperating `with the feed screw and arranged to either constitute a travelling nut and move in response to the turning of the feed screw, or toconstitute afixednut f' for the purpose of adjusting .the spaced 2c supports.y

head stocli, a. pair of spaced supports, slidably mounted on the'base, ineans for fixing the supports in position, a feed screw rotatively but non-slidabl'y attached to the spaced supports `and adapted to maintain'them at a fixed distance apa-rt, a motor on onek of the supports for driving the feed screw, and

aftail stockslic'lable onuthe hase and eo-4 .Operatlng with the feed screw.'

l 9. A boringmachine comprising a bed, a head stock, a pair ofspaced supports slidably mounted on the base, means for fixing the `supports in position, affeed screw rotatively but non-sli-dably attached to the spaced supports `and adapted to maintain them ata fixed distance apart, a motor on one of the supports for driving 'the feed screw, a tail stock slidable on the base and cooperating with the feed screw, and means for affixing the tail stock tothe hed for Vthe i pupose of adjusting the spaced supports and the feedscrew.

10.The combination as in claim 6, said means comprising a rotatable shaft which is axially movable relatively tov said support.,l v.

1l. The combination as in claim 6, said means comprising a-rotatable shaft and a Vclutch between the shaft and screw.

12. The combination as in claim 2, said means comprising a rotatable shaft which is `axially movable relatively to said supports and a clutch between said shaft and screw.

13. A boringmachine comprising a bed, a boring` bar, a fixed bar support, a spaced support, a feed screw driving shaft, a feedscrew rotatively but non-slidably connected to said spaced. supports, a tail stock movable onthe bed and cooperating; with the feed screw, and' independent driving means on onekof said supports adapted to be connected tothe feed SClTow;

le. A boringl machine 'comprising a bed, a boring bar, a fixed bar support, a spaced support, a feed screw drivingy shaft, a feed yscrew rotatively but non-slidably connected to said spaced supports and maintaining said supportsv in spaced relation, a tail stock movable on 'the bed and cooperating with the feed screw, anda driving motor on one of said' supports operatively connected to the v v "screw above the surface ofthe bed rotatively l8. A boring machine.comprisingl a hechar,

butnon-slidably secured to the spaced supports, and Agearing for connecting the sections of the feed screw together.

l?. AL boring machine comprising a bed,

a lpair of spaced supports, a feedscrew driving sha-ft below the surface of the bed, a feed lSJA boring' machine comprising a, bed,

a head stool; affixed thereto. at rone, end, a

tail stock slidably mounted .on the bed, al

boring bar afiixedto the tail Stock and extending' 'toward the head stock, a support for the boring' bar slidable on the bedand adapt-od to'be affixed thereto, aisecond support beyond the tail stock slidable on the bed and adapted to be affixed thereto, a feed screw cooperating with the tail stock and rotatively but not slidably affixed to said spaced supports, and means on one of the spaced supports for driving the feed screw.

19. A boring' machine comprising a bed, a head stock affixed thereto 4at one end, a tail stoel; slidably mounted on the bed, a boring bar affixed to the tail stock and extending toward the head stock, a supporty for the boring bar slidable on the bed and adapted to be affixed thereto, a second support be-.l

boringy barl affixed to the tail stoel; and ern tending toward the head stock, a support for the boring bar slidable on the bed and adapted te be aixed thereto, a second support beyond the tail stock slidable on the bed and adapted to be afmxed thereto, a feed screw section cooperating with the tail stock and rotatively but non-slidably affixed to said spaced supports, a feed sereT driving shaft extending from the head stock to the fixed bar support, gearing between said shaft and the feed screw, and independent driving means on one of said fixed supports for the feed screw.

21. A boring machine eon'iprising a bed, a head stock aixed thereto at one end a tail Stoch slidably mounted on the bed, a. boring bar affixed to the tail stock and extending toward 'the head stock, a support for the boring bar slidable on the bed and adapted to be affixed thereto, a second support beyond the tail stoc r slidablc on the bed and adapted to be aflixed thereto, a feed screw cooperating with the tail stock and rotatively but non-slidably affixed to said spaced supports, a feed screw driving shaft extending from the head ck to the Vxed bar support, and a releasabf. oriving connection between said shaft and the feed screw.

A boring machine comprising a bed, a head stock aiiixed thereto at one end, a tail stock slidably mounted on the bed, a boring bar afiixed to the tail stoclr and extending toward the head stock, a support for the boring bar slidable on the bed and adapted to be affixed thereto, a second support beyond the tail stock slidable on the bed and adapted to be aiixed thereto, a feed screw cooperating with the tail stock and rotativcly but. non-slidably affixed to said spaced supports, a feed screw driving shaft extending from the head stock to the fixed bar support, a releasable driving connection between said shaft and the feed screw, and an independent d 'iving motor on one of the spaced supports operatively connected to the feed screw.

28. A boring machine comprising a bed, a head stock ai'lixed thereto at one end, a tail stock slidably mounted on the bed, a boring bar affixed to the tail stock and extending toward the head stock, a support for the boring bar slidable on the bed and adapted to be affixed thereto, a second support beyond the tail stock slidable on the bed and adapted to be affixed thereto, a feed screw section cooperating with the tail stock and rotatively but non-slidably affixed to said spaced supports, a feed screw driving` shaft extending from the head stock to the fixed bar support, a releasable driving connection between said shaft and the feed screw, and an independent driving motor on one of the spaced supports releasably connected to the feed screw.

24. A boring lathe comprising a bed, a head stock, driving means, a fixed bar support slidable on the bed and adapted to be affixed thereto, a spaced support also slidable on the bed and adapted to be fixed thereto, a feed screw section rotativeljv but non-slidably mounted in said spaced supports and constituting a connection between them, a tail stock slidably mounted on the bed and having a relatively fixed nut cooperating with the feed screw, a boring bar extending through the fixed bar support, and secured to the tail stock, a driving feed screw shaft below the surface of the lathe and connected to the driving means at the head stock, releasable gearing between said shaft and the feed screw, and a quick return feed screw driving motor on one of said spaced supports.

25. A boring machine comprising a fixed bar support, a tail stock for feeding the bar, a feed screw for feeding the tail stock, an intermediate bar support, and rotatable means for causing the intermediate bar support to maintain its spaced relation irrespective of the position to which the tail stock may be adjusted.

26. A boring machine comprising a fixed bar support, a tail stock for feeding the bar, a feed screw for feeding the tail stock, an intermediate bar support, a nut on the feed screw rotatable on the intermediate bar support, and means for driving the rotatable nut at a speed which is slower than that of the feed screw.

27. A. boring machine comprising a xed bar support, a tail stock for feeding the bar, a feed screw for feeding the tail stock, an intermediate bar support, a nut on the feed screw rotatable on the intermediate bar support, and means for driving the rotatable nut at a speed which is different from that of the feed screw.

28. A boring machine comprising a ixed bar support, a tail stock for feeding the bar, a feed screw for feeding the tail stock, an intermediate bar support, 'and means responsive to the feed screw for driving the rotatable nut at a speed which is slower than that of the feed screw.

29. A. boring machine comprising a fixed bar support, a tail stock for feeding the bar, a feed screw for feeding the tail stock, an intermediate bar support, and a gear slidable on the feed screw and operativel;7 connected to the rotatable nut for driving the nut at a speed which is different from that of the feed screw.

30. A boring machine comprising a fixed bar support, a feed screw, a tail stock having a complete nut cooperating with the feed screw, and an intermediate screw actuated bar support between the tail stock and the fixed bar support. f

3l. A bowing machine eomprsng a fixed In Witness whereof I hve herennto set bar support, a, feed screw, a tail, steek hawn my hand this 17th day -of August, 1918.

king Complete nut cooperating with the feed screwz an intermediate bm support between ROBERT L HIBBARD' the tall sto/ck and the Xed bar suppot, and Witnesses: :L feed screw support Cenneeted to the 'nter- AUG J. SCHMITT,

4 mediate han support and movable therewith. PATRICK MGCABE. 

